Smart Drugs,

#143: Methylene Blue: An Unexpected Cognitive Enhancer

August 26, 2016

When you think of cognitive enhancers, what comes to mind?  Caffeine, herbs like Bacopa Monnieri, maybe Modafinil…  but probably not a substance that has been used as a textile dye or a parasite treatment for fish, right?

Meet Methylene Blue, a memory enhancer, antioxidant, and neuroprotectant.

Jesse talks to Dr. Francisco Gonzalez-Lima of the University of Texas at Austin about his work studying the benefits of methylene blue and why this impressive smart drug isn’t more widely known.

A Cognitive Enhancer That Turns Your Pee Blue

It’s in the name — methylene blue is blue.  That’s why it was used as a dye for textiles as early as 1876.

And also why it’s been used by pranksters to turn their victims’ pee blue.

But it’s way more than that.

As early as 2002, Dr. Gonzalez-Lima has been studying the cognitive enhancing properties of methylene blue.

It improves the oxygen consumption of cells, increasing cellular energy, which in turn enhances memory — both long- and short-term — is neuroprotective, and is an antioxidant.

In the words of Dr. Gonzalez-Lima, there’s “no better antioxidant.”  Because it accumulates in areas of cells with a high concentration of mitochondria, it stops free radicals as they are formed, preventing any oxidant damage or stress.

It’s a particularly effective cognitive enhancer because methylene blue targets “respiring cells” — cells that are using more oxygen.  The brain is an oxygen hog, so methylene blue collects there.

How To Take Methylene Blue

Methylene blue has a hormetic dose response (for more on hormesis, check out Episode 108), meaning that low doses are beneficial, while high doses are harmful.  Intermediate doses have no effect.

So what’s a safe dose?  Don’t take more than 5mg per kilogram of body weight (and take less if you are obese).  Anywhere from 0.5mg – 5mg per kilogram is safe and effective.

But at high doses, watch out!  It interferes with the ability of red blood cells to carry oxygen and can be fatal.

Keep in mind that methylene blue has a long half-life — 12 hours to be exact.

Don’t Buy It At the Pet Shop

Bizarrely, for a cognitive enhancer, you can buy methylene blue at a pet shop.  But just because you can, doesn’t mean you should.

It’s available in three categories of purity, and there’s only one purity level appropriate for human consumption:  Pharmaceutical Grade (USP).  To get this grade, you’re going to need a prescription and a compound pharmacy to prepare it.

The good news is that there are enough off-label uses for methylene blue found in the scientific literature that your doctor should be amenable to prescribing it for you.

That stuff you get at the pet store to eliminate parasites in fish?  It’s 85% purity (or less), and you should definitely not use it.

PS:  For more cognitive enhancing tips that don’t involve turning your pee blue, join our weekly Brain Breakfast!

Show Notes
  • 00:00:22

    Methylene Blue

  • 00:01:31

    This Week in Neuroscience: Aren’t You Dying to Know What This Story Is About?

  • 00:04:17

    The audience interaction section

  • 00:06:47

    Intro to Dr. Francisco Gonzalez-Lima

  • 00:08:05

    The history of Methylene Blue and the ”magic bullet”

  • 00:12:18

    Memory enhancement improvement

  • 00:12:56

    What is the half-life of Methylene Blue?

  • 00:15:17

    Proper dosages

  • 00:19:51

    How Methylene Blue works in the body

  • 00:24:23

    Methylene Blue versus near-infrared light

  • 00:28:54

    Are there any downsides to Methylene Blue?

  • 00:30:43

    How Methylene Blue fights parasites

  • 00:32:00

    Purity, safety, and over-the-counter status in the U.S.

  • 00:38:05

    Other helpful uses for Methylene Blue

  • 00:39:33

    Ruthless Listener-Retention Gimmick: How social media affects real-life social networks


  1. R Helms says:

    What reasons can I give to get a prescription for methylene blue? I believe Dr. Gonzalez-Lima said you could get a presciption for a number of reasons, but did not list them.

    1. Jesse Lawler says:

      We’ll reach out and see if he has some likely recommendations… Although depending on your doctor, you might just try the honest truth: “Hey, I’m interested in this for _________.”

    2. Michelle Silbernagel says:

      Follow up from Dr. Gonzalez-Lima regarding reasons methylene blue are typically prescribed:

      1. The oldest medical uses have been for malaria and treatment of urinary tract infection.
      2. MB is currently prescribed for several other medical conditions, including methemoglobinia, cyanide poisoning, azide poisoning, carbon monoxide poisoning, nitrite poisoning and other types of metabolic poisoning for which there is no other antidote.
      3. For the brain, it has been used for bipolar disorder and depression.
      4. I would predict that it has been also prescribed for others conditions for which improving brain energy metabolism would be beneficial, such as improving cognitive function and preventing neurodegeneration, but there are no definitive studies done on these other potential applications.
      4. MB is now undergoing clinical trials for mild cognitive impairment and dementia.

      Hope this information helps!

  2. R Helms says:

    I like the depression idea. I do take medication for depression – and I know that you should be careful mixing SSRIs and MB – and that might be an avenue to explore. Thanks!

  3. Rui says:

    Its possible with doses taked in micrograms, have effects?
    I see many people take it in 50mcg its ridiculous low dose

  4. Lauren says:

    I am currently taking vyvanse for ADHD. Will a single small dose have negative interactions? I saw that this chemical is considered an MAOI…

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Scroll to top